A practicing CISO's perspective on managing information security in large enterprises.

Sunday, October 18, 2009

Visa Embraces End-to-End Encryption

It feels like it has been a slow last few months in the information security regulatory and compliance space. That is my excuse for why it has been quiet on this blog for a while (well, that and being very busy with other stuff).

PCI was back in the news last week with an announcement by Visa in support of end-to-end encryption. With all the hundreds of requirements that PCI imposes on merchants, it can come as a bit of a surprise that data is not in fact encrypted at all stages as it travels between the Point-of-Sale and the card brand. This latest announcement by Visa is a signal that the payment industry is finally looking to fix this.

Further evidence of this shift comes from an unexpected source. This week I had the chance to hear Heartland CEO Bob Carr talk at the SC World Congress in New York about the massive data breach his company experienced in January of this year. Now you might think that the Heartland CEO addressing a security conference would be as likely as Nancy Pelosi addressing the NRA. But ever since Heartland's data breach, Carr has been aggressively engaging the IT security community.

He has called for reform of the QSA system (more on that later) and Heartland is promoting a new end-to-end encryption standard being developed with Voltage called E3. The E3 system will ensure encryption of card data from the moment a card is swiped until it is transmitted to the card brands.

Heartland is not alone in proposing a more robust system for securing card data throughout the transaction lifecycle. First Data and RSA have a competing tokenization product that basically replaces sensitive card data with random numbers and offers both advantages and disadvantages when compared with the E3 end-to-end encryption approach.

So will these new technologies reduce the number of credit card data breaches? That is hard to say, because we don't know enough about the cause of most of these breaches. But it seems like a safe bet that implementing these systems will at a minimum substantially reduce the risk of data compromise between the PoS and the acquirer.

But What About Internet Sales?

Card Not Present (CNP) transactions are a different ball game. After all, card data in a CNP transaction needs to travel a long road before it is safely in an end-to-end or tokenized environment. Removing the number of nodes that store actual unencrypted data will not do anything to secure these initial stages of CNP transactions. But it will make it easier to identify where breaches occurred. And this, in turn, will help sort out the liability issues which are at the heart of the practical problems with PCI.

Untangling the Liability Mess

Let's take a closer look at the liability issue. One reason for the poor state of application security today is that organizations are often not held accountable for data breaches that do not involve card holder data. With nearly ubiquitous data breach laws in effect, this is usually not the result of willfully concealing a breach but rather because companies don't know - and aren't motivated to uncover - whether they have been breached. In an ecosystem where many parties have handled the same data set, breaches cannot be definitively traced back to the offending party. This leaves little inherent incentive to invest in security technologies.

Take for example the fraudulent use of Social Security Numbers. If a criminal manages to take out fake credit in the name of a certain John Smith through use of his SSN, address, and birthdate, there is almost no way to realistically figure out where the leak came from. After all, John Smith has probably directly and indirectly provided this information to gazillions of service providers and others over time.

Cardholder data is a different ball of wax. The payment card industry is in a unique position to trace back its fraud and does this very successfully in the physical world. A waitress who runs cards through a skimmer in the back of the restaurant will lead to a list of fraudulent charges that will in all likelihood be traced back to the merchant. So the restaurant is incentivized (have never really been sure if that word actually exists) to prevent such fraud - whether by trying to hire trustworthy employees, keeping a closer eye on employees, etc.

In the Card Not Present environment, the lack of end-to-end encryption makes pinpointing blame slightly more difficult since the identical data set may exist in a number of different systems belonging to different entities. Perhaps not more difficult in a breach on the scale of Heartland, but more difficult for the thousands of mini-breaches that occur all the time. By securing this travelling data, it becomes easier to actually locate where smaller scale breaches have happened.

The Failure of the QSA System

As the screws tighten on data-in-transit and it becomes easier to assign blame for misused cards, the issue of QSA liability becomes even more important.

The QSA system is badly broken, and Heartland is just another example of a certified entity that was breached shortly after certification. The lack of liability is the greatest failure of the PCI system. In a normal financial audit, part of the deal is that if the company totally opens its books and does nothing to willfully mislead its auditor, then the auditor takes a certain liability with regards to the statements it produces. With PCI, nothing of the sort exists. What is the PCI audit worth if no one is responsible for its conclusions?

(The oft-quoted notion that one is never truly PCI compliant because compliance is a just snapshot in time doesn't hold much water. After all, a financial audit is also just a snapshot in time, in the sense that if someone raided the corporate bank account a week after an audit then of course the audit results are no longer valid. Liability can exist even without continuous monitoring)

Small Businesses

The liability issue is especially critical for small businesses. Although PCI has been around for a while, there are still a vast number of the 6 million odd smaller merchants in the US whose only experience with PCI is a line item on their merchant fees (many acquiring banks actually itemize a "PCI fee" to merchants). The credit crisis has left smaller merchants in a precarious situation, with merchant accounts being shut down when accounts exceed normal charging activity. Add PCI fines to the mix and a small company could easily go out of business altogether if it falls afoul of its acquiring bank.

Which means that in the short-term, increased awareness of PCI is driving an increased use of external payment gateway systems to offload card processing altogether. Most gateways are relatively inexpensive (small monthly fees and a small per transaction fee). It seems unlikely that any small company can invest the necessary funds to really make their IT systems PCI compliant. Data security regulations like the Massachussetts law go to great lengths to emphasize that small businesses are only expected to spend relative to their size. PCI is less forgiving. Level IV merchants may be under less validation requirements than Level I merchants, but the actual requirements are the same. It is no wonder that merchants are exiting the online payment business completely.

Of course those small businesses still have to deal with the PCI requirements for their non-Internet processing, but increasingly these IT environments are separate from a company's web presence. Many companies are outsourcing this processing as well. Indeed, significant amounts of card data can pop up in unlikely places. A recent British survey revealed that 97% of call centers record sensitive card holder data data. Better to have those systems outside the gate as well.

The new move to end-to-end encryption is certainly good news for the payment card industry, but will also require businesses to invest in new equipment and generally reassess their card payment architecture. For many small web merchants it may well serve as a motivation to reduce their card gathering activities even further.

2 comments:

It's nice to hear that end-to-end encryption is still gaining traction, even if hearing Carr say it gives me a face like I'm eating too-sour grapes. I also don't look forward to our typical US (or capitalist) way of solving such issues by competition rather than cooperation. We might never get it done right or we might have splintered solutions.

I'm not sure I'd call QSAs broken, if only because of subtle nuances. I think the QSA function is a symptom of the problem (?) of infinite range of IT/app solutions. With finances (and I could be wrong since I'm not in that field) you only have so many broad methods of accounting and finance such that you can pretty much analyze and compare companies easily. With IT, it seems like the environments can be infinitely complex and varied, which makes the QSAs job difficult if not ultimately impossible to the degree most people think compliance and security are tested (it's secure!).

Anyway... :) Thanks for the thought-out post! I'm not too into the nuts and bolts of card data transactions, but posts like yours help keep me informed!

Thanks for the comment and you make a great point about the proliferation of IT systems. A QSA cannot be expert - or even familiar - with the majority of systems, platforms, OSes, etc that are out there. Current requirements for becoming a QSA focus on CISSP/CISA/CISM type qualifications but there is no specific technical requirement as far as I know.

The part of the QSA system that needs fixing is the motivation of the assessor. Since most QSAs work on a fixed price model and want to ensure steady business, it is not really in their interest to inconvenience the company they are assessing. This is also true of many financial audits, but at least in that case the auditors are held accountable (both legally and in the popular press) for failure to uncover financial irregularities. There have been very few cases where QSAs have faced similar scrutiny when a PCI compliant company has been breached. In the case of Heartland their QSA was Trustwave but they were contractually prevented from suing them.